In recent years, electric propulsion vehicles known as environment-friendly cars have been developed at a rapid rate. Charging infrastructures for electric propulsion vehicles are roughly classified into two types of charging facilities: home charging facilities utilizing home power supplies that are terminals of a power network; and public charging facilities provided, for example, in urban areas or under road surfaces and based on the assumption that the facilities are used by the general public.
With convenience taken into account, home charging facilities are needed in order to spread electric propulsion vehicles. Thus, slow charging facilities using commercial 100- or 200-V power supplies have started to be introduced into households, offices, and the like.
To charge a battery for an electric propulsion vehicle using a home charging facility, a charging cable for an electric propulsion vehicle is used to connect an electric outlet for a commercial power supply and a connector on the electric propulsion vehicle side together.
The charging cable for the electric propulsion vehicle includes a power plug for connection to the electric outlet for the commercial power supply and a charging plug for connection to the connector on the electric propulsion vehicle side. The charging cable is used in charging the battery by inserting the power plug into the electric outlet disposed on an outer wall of a house or the like.
The charging cable for the electric propulsion vehicle may suffer abnormal heat generation caused by an incomplete connection between the electric outlet and the power plug or a tracking phenomenon. Thus, a charging cable has been proposed which is provided with a temperature sensor that senses the temperature of the power plug (see, for example, Patent Document 1). If the temperature of the power plug exceeds a predetermined value, a control signal is transmitted to a switching circuit that turns on and off an electric circuit between the power plug and the charging plug. This stops power supply from the power plug to the connector on the electric propulsion vehicle side.
However, the charging cable in Patent Document 1 fails to definitely describe the recovery of the temporarily stopped power supply. Thus, according to Patent Document 1, charging may be terminated when the power supply is temporarily stopped. For the home charging facility, desirably, for example, if a user gets home at night and starts charging the battery, the battery will have been fully charged by next morning when the user goes out. Therefore, the home charging facility is faced with a demand to ensure as long a period of charging as possible.
There are various possible factors contributing to abnormal heat generation. Abnormal heat generation may not occur when charging is resumed. Furthermore, abnormal heat generation may be avoided by changing charging conditions. Thus, even when abnormal heat generation occurs, termination of the charging prevents satisfaction of the demand to ensure as long a period of charging as possible.
Patent Document 1: Japanese Patent Application Laid-open No. 2010-110055